[drphoto]

I finally got the wiring sorted out on my H-frame servo subs and they sound great. (see other post)

However, now that the weather has cooled down and I've turned off all fans in the house, I've noticed a low level 60hz hum coming from one of them. I tried a cheater plug and even running the AC to another outlet (different circuit) to no avail. Any thoughts?

It's definitely coming from the speaker, not a mechanical hum from the plate amp. It is low in volume, but the other unit is dead quiet.

Oh....it happens w/ the rest of the system OFF too, so it's not preamp noise.

[Guy 13]

I finally got the wiring sorted out on my H-frame servo subs and they sound great. (see other post)

However, now that the weather has cooled down and I've turned off all fans in the house, I've noticed a low level 60hz hum coming from one of them. I tried a cheater plug and even running the AC to another outlet (different circuit) to no avail. Any thoughts?

It's definitely coming from the speaker, not a mechanical hum from the plate amp. It is low in volume, but the other unit is dead quiet.

Oh....it happens w/ the rest of the system OFF too, so it's not preamp noise.

Hi all AC members.
I have exactly the same problem as above.
Minds you, to hear the hum, I must have my ear against the cone of the driver.
I am relocating the Rythmik plate amplifier away from the crossover and re-wiring the complete V-1, I will find out in a week if the problem is gone.
Guy 13.

[Tyson]

You should unplug the preamp, both the power cord and the interconnects, then you can tell truly if it's the preamp or not.

[Guy 13]

You should unplug the preamp, both the power cord and the interconnects, then you can tell truly if it's the preamp or not.

Hi Tyson.
I don't have a pre-amplifier, it's an integrated NS-15 from Niteshade Audio
and I just took apart my V-1 for re-wiring and re-location of the Rythmik plate amplifier and some wood cabinet modifications as per Danny's recommendations.
If when it's all put back together, I still have the same problem, I will get back to Audio Circle for help.
Thanks and have a nice day.
Guy 13.

[Danny Richie]

Every now and then there is a transformer that wants to hum. So far Brian has been very good about taking care of it.

[drphoto]

Should I send it back? I think it's maybe a year old.

[Danny Richie]

Contact Brian and ask him about it.

[rythmik]

Contact Brian and ask him about it.

Check if this is a ground loop problem, which is hum from speakers, but not from the transformer. To root cause ground loop, you need to physically disconnect any interconnect between the subs and the rest of the system.  Let me know if that changes the hum.  Sometimes bad interconnect with poor or no ground connection can also cause hum. In this case, after you unplug all interconnects from the sub, it will be gone because bad interconnect acts as an antenna.

[drphoto]

Well, another embarrasing situation, but I'll fess up to save someone else the same problem.

The hum came from a loose interconnect, but not to the subs, but to the mains amp. It fooled me, because the monitors sounded fine. Once I got it seated correctly all is good.

Thanks for the replies.